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CT03 Series
Encapsulated THT Current Sense Transformers
The CT03 Series is a through-hole (THT) current sense transformer family designed for higher-current applications, offering primary-current capability up to 25 A. With a maximum height of 22.1 mm and a maximum footprint of 10.2 × 17.3 mm, it is engineered to deliver reliable, isolated current sensing in power supplies, converters, and protection circuits where larger currents or easier installation are required.
Featuring a variety of turns ratios — from 1:50 to as high as 1:1000 depending on the part — CT03 provides designers with flexibility for sense-voltage scaling and burden-resistor selection. Its guaranteed 3750 VAC isolation, wide –40 °C to +130 °C operating range, and robust encapsulated construction make CT03 suitable for industrial, telecom, and distributed-power environments needing dependable current measurement.
Key Features
- Through-hole encapsulated current-sense transformer
- 10.2 × 17.3 mm compact THT footprint, 22.1 mm max height
- Supports primary currents up to 25 A
- Supports SMPS switching frequencies up to 400 kHz
- 3750 VAC primary-to-secondary isolation (Hi-Pot tested)
- Turns ratios from 1:50 to 1:1000
- Meets UL1950 and EN60950 creepage and clearance spacing requirements
APPLICATIONS
- DC/DC and AC/DC converters requiring isolated current sensing
- Feedback and control loops operating at switching frequencies up to 400 kHz
- POL (Point-of-Load) regulators requiring isolated current sensing
- Overload, short-circuit, and over-current protection monitoring
- Industrial and embedded power systems requiring isolated current sensing
- Load-drop detection and power-fault monitoring
- DC/DC and AC/DC converters requiring isolated current sensing
- Feedback and control loops operating at switching frequencies up to 400 kHz
- POL (Point-of-Load) regulators requiring isolated current sensing
- Overload, short-circuit, and over-current protection monitoring
- Industrial and embedded power systems requiring isolated current sensing
- Load-drop detection and power-fault monitoring
Electrical Specifications @ 25°C - Operating Temperature Range1: -40°C to +130°C
Part Number
Turns Ratio
(TR)
Secondary Inductance2 (mH,Min)
Secondary DCR (Ω,Max)
Current
Rating3
(A,Max)
SRF4 (3-1) (kHz,Typ)
ET Product7
(V-μs, Max)
Hi Pot (VAC)
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1.
Operating Temp. Range: The combination of ambient temperature and temperature rise.
-
2.
Secondary Inductance: Tested @ 17.5KHz, 1VRMS, Series. CT03-1000-A is tested @ 1KHz, 1VRMS, Series.
-
3.
Current Rating: The primary current rating is for reference only and is limited by the current capacity of the customer-supplied primary conductor.
-
4.
SRF: Values are for reference only.
-
5.
Flammability Standard: Meets UL 94V-0.
-
6.
Terminating Resistor (RB): To calculate the value use the formula,
RB = EOTR/IP -
7.
ET Product: The maximum ET is based upon a flux density of 3700 Gauss at 25°C. Suitable for bipolar applications only.
ET = EO/2f
EO = IPRB/TRWhere as,
EO = Output voltage (V) TR = Turns Ratio
RB = Term. Resistor (Ω) f = Frequency (Hz)
IP = Primary Current (A)P/N Designator Suffix:
C – Center Tapped Secondary
N – Non-Center Tapped Secondary -
8.
PACKAGING
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Pieces/Tray: 270
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Trays/Box: 5
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Pieces/Box: 1350
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Specifications subject to change without prior notice.